The subject matter disclosed herein generally relates to a thrust vector actuator for directing the thrust of a rocket engine and absorbing rocket engine transient loads.
Rockets may be used to launch payloads into space, including inserting payloads into various orbits around the earth or other celestial bodies and/or directing payloads through space. Rockets are maneuvered by vectoring a rocket engine thrust direction. In some configurations, a thrust vector control system may be configured to use hydraulic rams to displace an engine nozzle angle relative to a rocket core axis to control a thrust vector to ensure proper propulsion of the rocket. Hydraulic rams require high pressure hydraulic fluid pumping systems capable of providing, for example, up to 4000 psia at flow rates of 40-100 gallons per minute or greater.
In some systems, during a rocket engine's start cycle, a large transient force can be applied to the thrust vector control actuators. This transient force may be several times larger than the normal maximum force applied to the actuator during normal operation. Hydraulic actuators are traditionally used in rockets because they incorporate hydraulic high pressure relief valves, which allow the actuator to momentarily drift, relieving the load, during the high load, short duration transient events. Electro-mechanical actuators have been used in rockets because of their increased efficiency and reduction in the risk of leaks and fires. However electro-mechanical actuators do not have the same pressure relief capability of hydraulic actuators to absorb the escalated transient forces seen on engine start up. As such, electro-mechanical actuators must be designed robustly to be able to handle the escalated transient forces seen on engine start up. A more robust design often means larger and heavier components for the electro-mechanical actuator.
Such methods and systems have generally been considered satisfactory for their intended purposes. However, improved systems and particularly improved electro-mechanical thrust vector actuators may provide cost, efficiency, weight, and/or other benefits.